# N521AU: 1988 Boeing 737-3B7, registration cancelled 2007-05-04 - Type: Cancelled registration (FAA registry, deregistered aircraft) - Cancelled: May 4, 2007 - Exported to: Mexico - Status when cancelled: Valid registration - Airframe: [Boeing 737-3B7](https://openairdocs.org/model/boeing-737-3b7) (registry code 138447F) - Engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802) - Serial number: 23856 - Year built: 1988 - Type of aircraft: Fixed wing multi engine - Engine type: Turbo-fan - Airworthiness: Standard, transport - Airworthiness date: February 10, 1988 - Certificate issued: October 12, 2006 - Last registry action: October 12, 2006 - Mode S code: A68CB8 - Owner when cancelled: [737 Portfolio Trust](https://openairdocs.org/faa-owner/737%20PORTFOLIO%20TRUST) - Location: [Wilmington, DE](https://openairdocs.org/faa-place/DE/Wilmington) - Owner type: Corporation - Owner's area on the map: 39.7357° N, 75.5321° W: Placed by OpenAirDocs: center of Wilmington, DE, within about 2 miles (OpenAirDocs). The owner's mailing address, not where the aircraft was based - The mark today: https://openairdocs.org/aircraft/N521AU - FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=521AU - Page: https://openairdocs.org/deregistered/N521AU-2007-05-04 From the FAA registry file of November 5, 2026, cancelled registrations. Owners' street addresses are left out. The Mode S code belongs to the N-number, not the airframe. ADs and bulletins for the Boeing 737-3B7: https://openairdocs.org/model/boeing-737-3b7.md ## Service difficulty reports (103, newest 50) Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model. - [SDR USAA050151](https://openairdocs.org/sdr/USAA050151), Jan 13, 2005: SKIN. CRACKED. PIT - Q6 - PYLON STRUT SKIN, .7500 INCH CRACK; PYLON STRUT SKIN FOR LT ENGINE, ACCESS PANEL CUTOUT. STOP DRILL OF CRACK AND INSTALLATION AT DOUBLER IAW TYP REP - [SDR USAA050222](https://openairdocs.org/sdr/USAA050222), Jan 12, 2005: FLOOR SUPPORT. CORRODED. PIT - FOUND FLOOR SUPPORT CORRODED APPROX 3 INCHES BY .5 INCH, STATION 797 TO 817. FABRICATED AND INSTALLED NEW FLOOR SUPPORT PER SRM 53-00-53. (M) - [SDR USAA050189](https://openairdocs.org/sdr/USAA050189), Jan 12, 2005: BRACKET. CRACKED. PIT - FOUND DOUBLER BRACKET CRACKED, FS 500-500A, VHF NR 2 ANTENNA MOUNT BRACKET. REMOVED DAMAGE AND INSTALLED DOUBLER PER SRM 51-40-02. (M) - [SDR USAA050167](https://openairdocs.org/sdr/USAA050167), Jan 11, 2005: SKIN. CHAFED. PIT - FOUND SKIN CHAFFING AND FRETTING WEAR 25.5 BY 30 INCH, BS 860 BETWEEN STRINGER 3L AND 3R. DAMAGE REMOVED, DOUBLER INSTALLED PER SRM 53-60-01 FIG 209. (M) - [SDR USAA050162](https://openairdocs.org/sdr/USAA050162), Jan 9, 2005: BRACKET. CRACKED. PIT - Q6 - BRACKET, 10 INCHES LONG CRACK; VHF COMM ANT BRACKET, STA 500-500A FWD BAGGAGE PIT; REMOVED AND REPLACED CRACKED BRACKET, BLENDED CORROSION IAW SRM. ( - [SDR USAA050161](https://openairdocs.org/sdr/USAA050161), Jan 8, 2005: SKIN. CRACKED. PIT - Q6 - INNER SKIN, APPROX .5 INCH LONG; MAIN ENTRANCE DOOR AFT SIDE AT NR 7 STOP; INSTALLED DOUBLER IAW TYP REP. (K) - [SDR USAA050163](https://openairdocs.org/sdr/USAA050163), Jan 6, 2005: KEELBEAM. CRACKED. PIT - Q6 - KEELBEAM, 1 INCH CRACK; STA540 39R; REPLACED SECTION OF FWD KEELBEAM, SPLICES MFGD IAW TYP REP 53-60-09. (K) - [SDR USAA050164](https://openairdocs.org/sdr/USAA050164), Jan 3, 2005: INTERCOSTAL. CRACKED. PIT - Q6 - BAFFLE, 1 INCH CRACK; AFT CARGO BIN STA 927 S-25L; FABRICATED AND INSTALLED NEW BAFFLE IAW SRM. (K) - [SDR USAA050176](https://openairdocs.org/sdr/USAA050176), Jan 1, 2005: SKIN. CHAFED. PIT - FOUND LOWER SKIN SURFACE WITH CHAFE DAMAGE, 1.5 INCH BY 2.5 INCH, NR 2 SLAT INBOARD CORNER AND OUTBOARD CORNER LOWER SURFACE. (M) - [SDR USAA050175](https://openairdocs.org/sdr/USAA050175), Jan 1, 2005: FLOORBEAM. CORRODED. PIT - FOUND FLOORBEAM CORRODED .5 INCH BY .5 INCH AREAS AROUND 6 NUTPLATES, FLOORBEAM STATION 967 17L-17R. TOP CP REPAIR, FLOOR EXTRUSION AND SPLICES PER TYPICA - [SDR USAA050174](https://openairdocs.org/sdr/USAA050174), Jan 1, 2005: SUPPORT BRACKET. CORRODED. FOUND WALL SUPPORT BRACKET CORRODED 1 INCH BY .5 INCH AREA AROUND 6 SCREW HOLES, STATION 500D 26R-26L. REMOVED AND REPLACED WALL SUPPORT BRACKET. (M) - [SDR USAA050172](https://openairdocs.org/sdr/USAA050172), Jan 1, 2005: FLOOR SUPPORT. CORRODED. PIT - FOUND FLOOR SUPPORT CORRODED 1 INCH BY .5 INCH IN THREE AREAS, FLOORBEAM FROM STATION 967-986 LBL 18. DEFECTIVE PART REPLACED WITH IDENT PART PER SRM 51-1 - [SDR USAA050171](https://openairdocs.org/sdr/USAA050171), Jan 1, 2005: FLOORBEAM. CORRODED. PIT - FOUND FLOORBEAM CORRODED 18 INCHES LONG, LBBL 8 STATION 344. CORROSION LEVEL 1. WEB MFG PER 53-00-51 FIG 202. (M) - [SDR USAA050169](https://openairdocs.org/sdr/USAA050169), Jan 1, 2005: SKIN. DELAMINATED. PIT - FOUND COMPOSITE SKIN DELAMINATED 1 INCH AREA, RT AILERON TAB OUTBOARD T/E. INSTALLED REPAIR PLYS PER SRM 51-60-01 AND 51-70-16. (M) - [SDR USAA050168](https://openairdocs.org/sdr/USAA050168), Jan 1, 2005: SKIN. DELAMINATED. PIT - FOUND TOP SKIN/CORE BOND DELAMINATED 3 INCHES BY 2 INCHES AREA, NR 3 SLAT INBOARD T/E. REMOVED DELAMINATED TOP SKIN AND CORE MATERIAL, BONDED IN NEW CORE, - [SDR USAA050173](https://openairdocs.org/sdr/USAA050173), Jan 1, 2005: FLOORBEAM. CORRODED. PIT - FOUND FLOORBEAM CORRODED 1 INCH BY .75 INCH AREA, FLOORBEAM STATION 328 RBBL 24.50 LBBL 24.50. CORROSION LEVEL 1. REMOVED CORROSION, FABRICATED STRAP REPA - [SDR USAA050166](https://openairdocs.org/sdr/USAA050166), Jan 1, 2005: STRINGER. CRACKED. PIT - FOUND STRINGER CRACKED 1.5 INCHES LONG, FS 380 STRINGER 15R. SPLICED IN NEW SECTION OF STRINGER PER SRM 53-00-03, FIG 201, DWG 65-45768. (M) - [SDR USAA050165](https://openairdocs.org/sdr/USAA050165), Jan 1, 2005: CHANNEL. CRACKED. PIT - Q6 - CHANNEL, .7500 INCH CRACK; ST277, BL0, FWD CABIN FLOOR; DEFECTIVE PART REPLACED WITH IDENT PART IAW MFG DWG. (K) - [SDR USAA050160](https://openairdocs.org/sdr/USAA050160), Jan 1, 2005: SKIN. CRACKED. PIT - Q6 - NR 6 SLAT, .5 INCH CRACK; LOWER SKIN AFT ROW RIVET 4 INCHES FROM OB END; INSTALLED DOUBLER IAW SRM. (K) - [SDR USAA050159](https://openairdocs.org/sdr/USAA050159), Jan 1, 2005: INTERCOSTAL. CRACKED. PIT - Q6 - INTERCOSTAL, NUMEROUS CRACKS, .5 INCH. .7500 INCH, 1.5 INCH; SCREW HOLES UPPER FLANGE OF INTERCOSTAL, BS 380-400. REPAIR ANGLE INSTALLED IAW SRM. (K) - [SDR USAA050158](https://openairdocs.org/sdr/USAA050158), Jan 1, 2005: DOOR FRAME. CRACKED. PIT- Q6 - DOOR EDGE FRAME, .2500 INCH CRACK; FWD SERVICE DOOR, LOWER MIDDLE DOOR STOP CUTOUT, AFT EDGE FRAME; INSTALLED DOUBLER IAW TYP REP. (K) - [SDR USAA050157](https://openairdocs.org/sdr/USAA050157), Jan 1, 2005: DOOR FRAME. CRACKED. PIT - Q6 - DOOR EDGE FRAME, .1250 INCH CRACK; FWD SERVICE DOOR, UPPER MIDDLE DOOR STOP CUTOUT, AFT EDGE FRAME; INSTALLED DOUBLER IAW TYP REP. (K) - [SDR USAA050156](https://openairdocs.org/sdr/USAA050156), Jan 1, 2005: SKIN. CRACKED. PIT - Q6 - NR 1 SLAT, 1 INCH CRACK; LOWER SKIN AFT ROW RIVETS AT NR 2 AUX TRACK. INSTALLED DOUBLER IAW SRM. (K) - [SDR USAA050155](https://openairdocs.org/sdr/USAA050155), Jan 1, 2005: SKIN. CRACKED. PIT - Q6 - SKIN, APPROX 1 INCH CRACK; NR 2 ENG OB WING/LEADING EDGE AT SLAT STA3.25, LWR SKIN PANEL. FABRICATED SKIN FILLER/ DOUBLER IAW TYP REP. (K) - [SDR USAA050154](https://openairdocs.org/sdr/USAA050154), Jan 1, 2005: FLOOR SUPPORT. CRACKED. PIT - Q6 - FLOOR SUPPORT, 1 INCH CRACK; STA 540, BL0.0; REPLACED SUPPORT BRACKET IAW SRM 53-00-51. (K) - [SDR USAA040755](https://openairdocs.org/sdr/USAA040755), Oct 12, 2004: WINDOW FRAME. CRACKED. PIT, C5, WINDOW FRAME, .2500 INCH CRACK, CAPTAINS WINDOW POST BETWEEN NR 1 AND NR 2 WINDOWS TOP, FWD CORNER. INSTALLED DOUBLER IAW SRM, FIG 103. - [SDR USAA040754](https://openairdocs.org/sdr/USAA040754), Oct 12, 2004: KEELBEAM. CRACKED. PIT, C5, KEELBEAM, 2 INCH LONG CRACK, KEELBEAM RT SIDE JUST AFT OF STA 540. INSTALLED REPAIR ANGLE IAW EA 79268. - [SDR USAA040745](https://openairdocs.org/sdr/USAA040745), Oct 11, 2004: PRESSURE PANEL. CRACKED. PIT, C5; PRESSURE PANEL, 2 INCH CRACK. LT WHEEL WELL UPPER DECK, 30 INCH LT OF BL0. INSTALLED DOUBLER AND SHIMS IAW TYP REP 53-60-04A AND EA 79277. - [SDR USAA040744](https://openairdocs.org/sdr/USAA040744), Oct 11, 2004: SKIN. GOUGED. PIT, C5; SKIN WITH .5 INCH GOUGE, STA 767 AT 22L JUST BELOW STRINGER. DRILLED HOLE TO .250 INCH DIA, INSTALLED RIVET WET IAW SRM 53-00-01, FIG 219. - [SDR USAA040746](https://openairdocs.org/sdr/USAA040746), Oct 10, 2004: STIFFENER. CRACKED. PIT, C5; STIFFENER ANGLE, 3.5 INCH CRACK, LOWER AFT CORNER OF CARGO DOOR IN STIFFENER ANGLE. DEFECTIVE PART REPLACED WITH IDENT PN IAW JOB CARD J3-51-52301. - [SDR USAASB04073](https://openairdocs.org/sdr/USAASB04073), Jun 18, 2004: FUSE. INOPERATIVE. PHL - PILOT REPORTED THE SEAT ROW EMERGENCY LIGHTS, FROM ROWS 17 THROUGH 22, INOPERATIVE. MAINTENANCE REMOVED AND REPLACED THE 5 AMP FUSE IN THE POWER SUPPLY. O - [SDR USAA040052](https://openairdocs.org/sdr/USAA040052), Mar 2, 2004: SKIN. CRACKED. CLT - FOUND SKIN CRACKED 2 INCHES, FS 885 JUST ABOVE STRINGER S25R. INSTALLED DOUBLER PER SRM 53-00-01. (M) - [SDR USAASB03193](https://openairdocs.org/sdr/USAASB03193), Oct 26, 2003: WIRE HARNESS. MELTED. ON APPROACH TO CLT, AT 1,500 FT, ENTIRE FIRE CONTROL PANEL ILLUMINATED & ALL FIRE BELLS SOUNDED EXCEPT FOR APU. CREW ALSO RECEIVED A LT WING BODY OVERHEAT INDIC - [SDR USAASB03174](https://openairdocs.org/sdr/USAASB03174), Sep 28, 2003: INDICATION SYS. MALFUNCTIONED. CLT - FLT 1095 - DURING DESCENT INTO CLT FROM DFW, AT APPROXIMATELY 1,700 FEET, CREW ENCOUNTERED A SPLIT FLAP INDICATION. CREW BROKE OFF APPROACH, DECLARED AN E - [SDR USAASB03140](https://openairdocs.org/sdr/USAASB03140), Aug 20, 2003: BATTERY PACK. INOPERATIVE. MAINTENANCE REPORTED THE FORWARD CABIN EMERGENCY LIGHTS INOPERATIVE. MAINTENANCE REMOVED AND REPLACED A WEAK EMERGENCY BATTERY PACK. OPERATIONAL CHECK GOOD. (M) - [SDR USAA030160](https://openairdocs.org/sdr/USAA030160), Aug 18, 2003: SKIN. CRACKED. FOUND SKIN CRACKED 2 INCHES, STATION 727E AT S24L. INSTALLED DOUBLER PER SRM 53-00-01. (M) - [SDR USAASB03012](https://openairdocs.org/sdr/USAASB03012), Jan 18, 2003: WIRE. DAMAGED. GSO - MAINTENANCE REPORTED THE EMERGENCY LIGHTS ON SEATS 7 AND 18, LT SIDE, INOPERATIVE. MAINTENANCE REPAIRED WIRING ON SEATS 7ABC AND 18ABC. OPERATIONAL CHECK - [SDR USAASB02079](https://openairdocs.org/sdr/USAASB02079), Apr 20, 2002: PROXIMITY SENSOR. FAULTY. RIC - FLT 1039 - NOSE GEAR RED AND GREEN LIGHTS WERE ILLUMINATED WHEN THE GEAR HANDLE WAS IN THE UP POSITION. CREW CYCLED THE GEAR. WITH HANDLE IN DOWN POSITION - [SDR USAASB02080](https://openairdocs.org/sdr/USAASB02080), Apr 20, 2002: RELAY. MALFUNCTIONED. RIC - FLT 1039 - NOSE GEAR RED AND GREEN LIGHTS WERE ILLUMINATED WHEN THE GEAR HANDLE WAS IN THE UP POSITION. CREW CYCLED THE GEAR. WITH HANDLE IN DOWN POSITION - [SDR USAASB01268](https://openairdocs.org/sdr/USAASB01268), Sep 23, 2001: BATTERY PACK. DISCHARGED. CLT - DURING OVERNIGHT CHECK, MAINTENANCE FOUND THE LAST SIX ROWS OF EMERGENCY LIGHTS INOPERATIVE. MAINTENANCE REMOVED AND REPLACED THE BATTERY PACK. OPERATIONA - [SDR USAASB01199](https://openairdocs.org/sdr/USAASB01199), Jul 10, 2001: LIGHT. INOPERATIVE. EWR - FOUND AFT GALLEY DOOR EXTERIOR EMERGENCY LIGHT INOPERATIVE. MAINTENANCE REPLACED THE LIGHT ASSEMBLY. (M) - [SDR USAA002072](https://openairdocs.org/sdr/USAA002072), Dec 6, 2000: STRINGER. CRACKED. CLT - FOUND STRINGER CRACKED 2 INCHES, BS 1141, STRINGER 5AL. INSTALLED REPAIR DOUBLER PER SRM 53-00-01. (M) - [SDR USAA002073](https://openairdocs.org/sdr/USAA002073), Dec 6, 2000: SKIN. CORRODED. CLT - FOUND EXTERIOR SKIN CORRODED 10 INCHES BY 20 INCHES, NR 3 VHF ANTENNA MOUNT STATION 727C AND 727E, LBL 5 TO RBL 5. CORROSION LEVEL 2 C53-107-02. INSTALLED - [SDR USAA002071](https://openairdocs.org/sdr/USAA002071), Dec 6, 2000: BEAM. CRACKED. CLT - FOUND SUPPORT BEAM CRACKED .250 INCH, LEFT MAIN LANDING GEAR SUPPORT BEAM. REPLACED MLG SUPPORT BEAM PER EA 68529. (M) - [SDR USAA002074](https://openairdocs.org/sdr/USAA002074), Dec 6, 2000: ANGLE. CORRODED. CLT - FOUND Z-ANGLE CORRODED 46 INCHES, SERVICE DOOR ENTRY STATION 294-340. CORROSION LEVEL 2 C53-107-02. INSTALLED SPLICE ANGLE AND SUPPORT ANGLE PER 51-10-02 - [SDR USAA002075](https://openairdocs.org/sdr/USAA002075), Dec 6, 2000: FLOORBEAM. CORRODED. CLT - FOUND T-CAP CORRODED, BS 344, LBL 10. CORROSION LEVEL 2 C53-107-02. INSTALLED NEW T-CAP PER SRM 53-10-51. (M) - [SDR USAA002058](https://openairdocs.org/sdr/USAA002058), Dec 4, 2000: FLOORBEAM. CORRODED. CLT - FLOORBEAM T-CAP CORRODED 1 INCH, BS 947.5, LBL 50 TO RBL 50. CORROSION LEVEL 2. REMOVED AND REPLACED FLOORBEAM T-CAP TR 53-10-05A. (M) - [SDR USAA002059](https://openairdocs.org/sdr/USAA002059), Dec 4, 2000: FLOORBEAM. CORRODED. CLT - FOUND FLOORBEAM CORRODED 1 INCHES, BS 967, LBL 41 AND 47.5. INSTALLED UPPER FLANGE/CHORD REPAIR PER TR 53-10-05A AND SRM 53-00-51. (M) - [SDR USAA002060](https://openairdocs.org/sdr/USAA002060), Dec 4, 2000: ANGLE. CORRODED. CLT - FOUND Z-ANGLE SUPPORT CORRODED 6 INCHES, BS 971 AT LBL 50. REPAIRED PER SRM 51-70-11 AND 51-10-2. (M) - [SDR USAAA002061](https://openairdocs.org/sdr/USAAA002061), Dec 4, 2000: FLOORBEAM. CORRODED. CLT - FOUND FLOORBEAM T-CAP CORRODED, STATION 986.5, RBL 50 TO LBL 50. CORROSION LEVEL 2. REMOVED AND REPLACED UPPER T-CAP PER TR 53-10-05A. (M) All 103: https://openairdocs.org/deregistered/N521AU-2007-05-04/reports.md --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.